Spring and bracket connection for platform-rockers



(No Model.)

' G. J. SHULTS. SPRING AND BRAOKET OONNEOTION FOR PLATFORM ROCKERS.

NO. 409.509. Patented Aug. 20, 1889.

UnrTEn STaTEs PATENT @EETQE.

GEORGE J. SHULTS, OF AVOCA, NEW YORK.

SPRING AND BRACKET CONNECTION FOR PLATFORM-ROCKERS.

SPECIFICATION forming part of Letters Patent N 0. 409,509, dated August20, 1889.

Application filed May 27, 1889. Serial No. 812,326. (No model.)

T0 (0% whom it may concern.-

Be it known that I, GEORGE J. SHULTs, a citizen of the United States,residing at Avoca, in the county of Steuben and State of New York, haveinvented new and useful Improvements in Spring and Bracket Connectionsfor Platform-Rockers, of which the following is a specification.

My invention relates to certain improvements in platform rocking-chairs,wherein a rocker-frame rests upon a stationary baseframe, and isconnected therewith and re tained in proper position relatively theretoby elastic connections attached to the rockerframe and base-frame,respectively, in alignment with the normal line of contact.

It is the purpose of said invention to 'provide simple, durable, andinexpensive springconnections consisting of spiral concentric duplexcoils formed of a single integral strand of suitable wire and providedwith attachingloops which engage with brackets upon the rocker and baseframes, the latter being so constructed as to provide seats in which thespring-attaching loops are securely and rigidly held, preventing anytendency to rotary displacement, but permitting the detachment andreattachment of the spring-loops at any time.

The invention consists in the several novel features of construction andcombinations of parts hereinafter set forth, and pointed out in theclaims.

Referring to the accompanying drawings, Figure 1 is an elevation of theinner face of one of the rockers and one side of the baseframe, showingthe spring attached. is a plan view of the parts shown in Fig. l.

Fig. 3 is a vertical section taken in the axial line of the duplex coilsand showing the same connected to the chair and base. Fig. 4. is adetail View showing the construction of the spring-connections. Fig. 5is a detail perspective of one of the brackets mounted on the rocker andframe. Fig. 6 is a partial section showing an inner and an outer springcoiled in opposite directions.

In chairs of this type various means have been devised for making anelastic connection between the base-frame and the rocker frame restingand. oscillating thereon. In one Fig. 2'

instance this connection has been formed of a strong endless band ofrubber stretched over pivots upon the parts connected. Coiled springshave also been used for a similar purpose, and in one instance thesesprings have been constructed in concentric duplex coils, but thesecoils were formed of separate strands of wire having entirelyindependent means of connection to the rockers and rails.

In carrying my invention into practice I mount upon the rocker-frame andbase-frame horizontally-projecting brackets 1., having angular lugs 2,which receive the attaching screws. These brackets are substantiallysimilar in form, each consisting of a flattened plate provided upon itsouter surface with a groove or channel 3, formed near and parallel withthe edge of the bracket-plate. At the ends of said groove the body ofthe bracketplate is cut away to form shoulders at, which are providedwith notches 5, in which the parallel arms of the wire loop lie, ashereinafter described.

The numeral 6 denotes a duplex spiral coil of spring-wire, consisting ofa main outer coil and an inner supplemental coil 7, concentric therewithand formed of an integral portion of the wire composing the outer coil.One terminal of the latter is formed into a halfloop 8, and the outercoil is then wound. From its last spiral the wire is bent to form theintegral loop 9, from which the continuous wire is coiled into the innersupplemental spiral, its other terminal being bent into the halfloop 10,which meets the other half-loop 8, both lying in one of the grooves orchannels 3 of the brackets, while the integral loop 9 lies in thecorresponding channel of the other bracket. \Vhen properly constructed,these loops will rest snugly in the channels of the brackets, and theirparallel arms will engage the notches 5 in the shoulders 4, therebyeffectively preventing rotary or lateral displacement. In operationthese springs, having different diameters, will possess differenttension under the same draft, the tension of the smaller or inner springbeing the greater. By this construction the elastic tension is not onlydivided between the inner and the outer springs, but as the formerapproaches its maximum resistance the latter begins to exert arapidly-increasing tension, which develops as the rocker approaches theextremes of its rocking movement, thereby relieving the inner spring ofsevere strain at these points, but exerting no material or appreciableinfluence at other points. I am thus able to protect the outer springfrom being wrenched apart or weakened by the rocking action, and therebygreatly promote its durability and improve the ease and uniformity ofthe oscillation of the chair. To facilitate the removal of these loopsof the spring-connections from the channels of the brackets in whichthey he, a notch or depression 12 is formed centrally in each of thebrackets to permit the insertion of a screw-driver, pick, or othersuitable instrument, under the loop as it lies in the channel 3. Byusing the tool as a lever the loop can be thrown off the bracket withoutdifficulty.

It will be seen that with a limited oscillation of the rocker-frame thecoils will be tilted or lifted upon opposite sides alternately, and inthis movement the strain will fall mostly upon the outer coil. WVith arocking movement of greater length the springs will be ex tended in thedirection of their axes, and here the inner coil will re-enforce andprotect the weaker outer coil from rupture or strain. I am thus ble toprovide an elastic connection which will exert materially differenttensions upon the'rocker, the lesser tension yielding readily to thegentle and slow vibration of the chair, while the longer rockingmovement will be resisted by the stronger and rapidly-increasing tensionof the inner spring as the rocking movement approaches its maximum.

The notches 5, formed at the ends of the channels 3 in the brackets, notonly prevent lateral displacement of the loops on the springcoils, asalready stated, but they also hold the divided loops formed by the freeends of the continuous wire together and prevent them from slipping outof the channels 3 in the brackets, whereby the coils would be caused tostrike each other, producing an unpleasant noise, besides causing themto wear rapidly. These shoulders. also center the coils and hold them inproper position relatively to each other. The inner and outer coils ofthe spring-connection are preferably wound in opposite directions, asshown in Fi 6, in order that any tendency to rotary displacement uponthe part of one coil may be normally counteracted by the other. In thismanner the annoying tendency of rockers of this class to work arounduntil they rock oif the base-frame may be effectively avoided. Ifpreferred, however, the two coils may be wound in the same direction, asshown in Fig. 3.

That I claim is- 1. The combination, with a duplex-spring connectionconsisting of outer and inner concentric coils formed of: a singlecontinuous spring-wire having loops, of brackets adapted to be mountedupon the rocker-frame and base-frame of a chair, respectively,substantially as described.

2. In a rocking-chair, the combination, with duplex springs composed ofinner and outer concentric coils formed of a single integral wire, ofbrackets adapted to be mounted upon the rocker-frame and base-frame, andprovided with grooves for said loops, and shoulders at the ends of saidgrooves, having notches which receive the parallel arms of the loops,substantially as described.

3. In a rocking-chair, the combination, with a stationary base-tram e,of a rocker-frame, and duplex elastic connections, each consisting of aninner and an outer concentric coil of one and the same continuous wirehaving loops which form part of each coil and lie in the channels ofbracket-plates mounted on the rocker-frame and base-frame, said bracketsbeing provided with shoulders at the ends of said channels, saidshoulders having notches receiving the parallel arms of the loops,substantially as described.

4. The combination, with the supportingbrackets adapted to be attachedto the rockerframe and base-frame of a chair, of a duplexspringconnection consisting of an outer and inner coil formed of a singlepiece of springwire, said coils being wound in opposite directions,substantially as described.

In testimony whereof I have affixed my signature in presence of twowitnesses.

GEO. J. SHULTS.

WVitnesses:

JAMES L. NORRIS, JAMES A. RUTHERFORD.

